issue #98 add type conversion for some assignments

ravi-tests/ravi_test_ast2.expected

@@ -506,6 +506,67 @@ function()
     false
 end
 
+function()
+--locals  t, len
+  local
+  --[symbols]
+    t --local symbol table 
+  local
+  --[symbols]
+    len --local symbol integer 
+  --[expressions]
+    --[unary expr start] integer
+    @integer
+     --[unary expr start] any
+     #
+      --[suffixed expr start] table
+       --[primary start] table
+         t --local symbol table 
+       --[primary end]
+      --[suffixed expr end]
+     --[unary expr end]
+    --[unary expr end]
+  return
+    --[suffixed expr start] integer
+     --[primary start] integer
+       len --local symbol integer 
+     --[primary end]
+    --[suffixed expr end]
+end
+
+function()
+  return
+    function(
+      t --local symbol table 
+     ,
+      i --local symbol integer 
+    )
+    --locals  t, i
+      --[expression statement start]
+       --[var list start]
+         --[suffixed expr start] integer
+          --[primary start] integer
+            i --local symbol integer 
+          --[primary end]
+         --[suffixed expr end]
+       = --[var list end]
+       --[expression list start]
+         --[unary expr start] integer
+         @integer
+          --[unary expr start] any
+          #
+           --[suffixed expr start] table
+            --[primary start] table
+              t --local symbol table 
+            --[primary end]
+           --[suffixed expr end]
+          --[unary expr end]
+         --[unary expr end]
+       --[expression list end]
+      --[expression statement end]
+    end
+end
+
 function()
    matmul --global symbol ? 
    =
@@ -573,45 +634,54 @@ function()
        ,
         x --local symbol table 
       --[expressions]
-        --[unary expr start] any
+        --[unary expr start] integer
-        #
+        @integer
-         --[suffixed expr start] table
+         --[unary expr start] any
-          --[primary start] table
+         #
-            a --local symbol table 
+          --[suffixed expr start] table
-          --[primary end]
+           --[primary start] table
-         --[suffixed expr end]
+             a --local symbol table 
+           --[primary end]
+          --[suffixed expr end]
+         --[unary expr end]
         --[unary expr end]
        ,
-        --[unary expr start] any
+        --[unary expr start] integer
-        #
+        @integer
-         --[suffixed expr start] any
+         --[unary expr start] any
-          --[primary start] table
+         #
-            a --local symbol table 
+          --[suffixed expr start] any
-          --[primary end]
+           --[primary start] table
-          --[suffix list start]
+             a --local symbol table 
-            --[Y index start] any
+           --[primary end]
-             [
+           --[suffix list start]
-              1
+             --[Y index start] any
-             ]
+              [
-            --[Y index end]
+               1
-          --[suffix list end]
+              ]
-         --[suffixed expr end]
+             --[Y index end]
+           --[suffix list end]
+          --[suffixed expr end]
+         --[unary expr end]
         --[unary expr end]
        ,
-        --[unary expr start] any
+        --[unary expr start] integer
-        #
+        @integer
-         --[suffixed expr start] any
+         --[unary expr start] any
-          --[primary start] table
+         #
-            b --local symbol table 
+          --[suffixed expr start] any
-          --[primary end]
+           --[primary start] table
-          --[suffix list start]
+             b --local symbol table 
-            --[Y index start] any
+           --[primary end]
-             [
+           --[suffix list start]
-              1
+             --[Y index start] any
-             ]
+              [
-            --[Y index end]
+               1
-          --[suffix list end]
+              ]
-         --[suffixed expr end]
+             --[Y index end]
+           --[suffix list end]
+          --[suffixed expr end]
+         --[unary expr end]
         --[unary expr end]
        ,
         { --[table constructor start] table

ravi-tests/ravi_test_ast2.lua

@@ -109,6 +109,20 @@ return false
 ]]
 doast(str)
 
+str=
+[[local t: table
+  local len: integer = #t
+  return len
+]]
+doast(str)
+
+str=
+[[return function(t: table, i: integer)
+    i = #t
+  end
+]]
+doast(str)
+
 str=
 [[function matmul(a: table, b: table)
   	assert(@integer(#a[1]) == #b);

src/ravi_ast_typecheck.c

@@ -29,9 +29,6 @@ static void typecheck_unaryop(struct ast_container *container, struct ast_node *
       if (subexpr_type == RAVI_TARRAYINT || subexpr_type == RAVI_TARRAYFLT) {
         set_type(node->unary_expr.type, RAVI_TNUMINT);
       }
-      else if (subexpr_type == RAVI_TTABLE) {
-        // FIXME we need insert a TO_INT expression;
-      }
       break;
     case OPR_TO_INTEGER:
       set_type(node->unary_expr.type, RAVI_TNUMINT);
@@ -190,25 +187,47 @@ static void typecheck_suffixedexpr(struct ast_container *container, struct ast_n
   copy_type(node->suffixed_expr.type, prev_node->common_expr.type);
 }
 
-static void typecheck_var_assignment(struct ast_container *container, struct var_type *var_type,
+static void insert_cast(struct ast_container *container, struct ast_node *expr, UnOpr opcode, ravitype_t target_type) {
-                                     struct var_type *expr_type, const char *var_name) {
+  /* convert the node to @integer node, the original content of node goes into the subexpr */
+  struct ast_node *copy_expr = dmrC_allocator_allocate(&container->ast_node_allocator, 0);
+  *copy_expr = *expr;
+  expr->type = AST_UNARY_EXPR;
+  expr->unary_expr.expr = copy_expr;
+  expr->unary_expr.unary_op = opcode;
+  set_typecode(expr->unary_expr.type, target_type);
+}
+
+static void typecheck_var_assignment(struct ast_container *container, struct var_type *var_type, struct ast_node *expr,
+                                     const char *var_name) {
   if (var_type->type_code == RAVI_TANY)
     // Any value can be assigned to type ANY
     return;
 
-  if (var_type->type_code == RAVI_TNUMINT || var_type->type_code == RAVI_TNUMFLT) {
+  struct var_type *expr_type = &expr->common_expr.type;
-    if (expr_type->type_code == RAVI_TNUMINT || expr_type->type_code == RAVI_TNUMFLT) {
+
-      // Okay
+  if (var_type->type_code == RAVI_TNUMINT) {
-      // TODO insert a typecast?
+    /* if the expr is of type number or # operator then insert @integer operator */
+    if (expr_type->type_code == RAVI_TNUMFLT ||
+        (expr->type == AST_UNARY_EXPR && expr->unary_expr.unary_op == OPR_LEN)) {
+      insert_cast(container, expr, OPR_TO_INTEGER, RAVI_TNUMINT);
     }
-    else {
+    else if (expr_type->type_code != RAVI_TNUMINT) {
+      fprintf(stderr, "Assignment to local symbol %s is not type compatible\n", var_name);
+    }
+    return;
+  }
+  if (var_type->type_code == RAVI_TNUMFLT) {
+    if (expr_type->type_code == RAVI_TNUMINT) {
+      /* cast to number */
+      insert_cast(container, expr, OPR_TO_NUMBER, RAVI_TNUMFLT);
+    }
+    else if (expr_type->type_code != RAVI_TNUMFLT) {
       fprintf(stderr, "Assignment to local symbol %s is not type compatible\n", var_name);
     }
     return;
   }
-
   // all other types must strictly match
-  if (!is_type_same(*var_type, *expr_type)) {  // We should probably check type convertability here
+  if (!is_type_same(*var_type, *expr_type)) {  // We should probably check type convert-ability here
     fprintf(stderr, "Assignment to local symbol %s is not type compatible\n", var_name);
   }
 }
@@ -232,10 +251,9 @@ static void typecheck_local_statement(struct ast_container *container, struct as
       break;
 
     struct var_type *var_type = &var->value_type;
-    struct var_type *expr_type = &expr->common_expr.type;
     const char *var_name = getstr(var->var.var_name);
 
-    typecheck_var_assignment(container, var_type, expr_type, var_name);
+    typecheck_var_assignment(container, var_type, expr, var_name);
 
     NEXT_PTR_LIST(var);
     NEXT_PTR_LIST(expr);
@@ -261,10 +279,9 @@ static void typecheck_expr_statement(struct ast_container *container, struct ast
       break;
 
     struct var_type *var_type = &var->common_expr.type;
-    struct var_type *expr_type = &expr->common_expr.type;
     const char *var_name = "";  // FIXME how do we get this?
 
-    typecheck_var_assignment(container, var_type, expr_type, var_name);
+    typecheck_var_assignment(container, var_type, expr, var_name);
 
     NEXT_PTR_LIST(var);
     NEXT_PTR_LIST(expr);